DESCRIPTION(Adapted from applicant's abstract): The long term goal of this application is to develop a simple blood-based assay for the early diagnosis of stroke. Although t-PA is an effective treatment for stroke it has been slow to be adopted, in part because it requires a diagnostic CT scan within 3 hours of the ischemic insult. Although this sophisticated technology is available at many urban facilities, its use and the interpretation of its results requires skilled physicians and technicians, available on an emergency basis. In contrast, the diagnostic method we propose, the measurement of serum unbound FFA (FFAu), involves a simple, inexpensive, virtually instantaneous, and readily accessible measurement that has high potential for revealing the ischemic event. In the proposed Phase I studies we will determine if plasma FFAU levels, measured with our ADIFAB fluorescence method, provide an early indicator of cerebral ischemia (stroke) in the rat. If, as we expect from studies of myocardial ischemia, that plasma levels of FFAu rise to very high levels within minutes following the ischemic insult, then we should be able to use the rat model to help define the characteristics of this assay in preparation for a Phase II trial in human patients. PROPOSED COMMERCIAL APPLICATION: If successful this research would demonstrate that unbound free fatty acids (FFAu) provide the earliest and most sensitive blood-assay based measure of cerebral ischemia. If supported by subsequent phase II and III trials, we would expect that, in conjunction with a small, inexpensive single purpose fluorometer, that this assay would be used exclusively to provide the earliest indication of stroke. This assay is based on our patented (US..) method which is only reported method for measuring FFAu, thereby ensuring considerable commercial application.